I will try to go through and help you out with the files you need to change....
You need replacement graphics however and thats not as easy as it sounds.
Ok lets pick the English for example and say you want to replace that leaderhead.
in the art subfolder go to advisors folder and there is a file called LZ all this is a set of 12 pics in a grid showing elizabeth in happy, neutral, and angry poses for each of the 4 eras. So in your scenario folder for your scenario or mod you need to make an art/advisors sub directory and put into this your replacement file, if you keep the names the same as the ones the game already uses then you wont have to edit the pedialicons file. (this particular graphics file is the one that is used on the military advisor screen)
now you also need to change out the files used for the game menu screen, and in the civpedia for the small picture under the tribes menu. These files are found in art/civilopedia/icons/races
and named Englishlarge and Englishsmall I believe, make your own appropriate set of folders and place your replacement graphics in races.
You further more need the flc files for the animation of the leaderheads and these go in art/flics
Lastly there is another set of files with the pics of the leaderhead in different poses that is used at the endgame screen, for example the beaten up pic when you lose a game. That is found in art/leaderheads and there are 10 files.
So you have to have all these replacement files and animations if you wish to change a leaderhead. If you change the name of the files from what is used by the game itself then you have to open the pedialicons file for your scenario or mod. The first section all the way down to the resources is the section where it tells the game where to look for these leaderhead graphics, and in this case you will have to go through and for every entry for england, change the string to point to your renamed files.
